Comparison of different formulation and boundary conditions for computational aeroacoustics

Computational aeroacoustics is a relatively new research area. There are a lot of techniques to predict the noise generated aerodynamically. A currently approach, to simulate aerodynamic noise on the near field is the use of the full and Linearized Euler Equations (LEE). Both approaches present advantages and drawbacks. The present paper presents the computations of the propagation of a gaussian acoustic pulse and compares numerical solutions with the analytical solution applying different boundary conditions for the Linearized and full Euler equations. For the Linearized Euler Equations the Perfectly Matched Layer and radiation and outflow boundary conditions are evaluated. A different numerical formulation is used to discretize the full Euler equation which is characteristic-based. In this case, a conceptual model based on the characteristic analysis is used to specify boundary conditions through the use of an absorbing zone. Numerical results are discussed shedding light on advantages and drawbacks of each technique.